Slashdot Mirror

You still get full specs from many companies. Free samples are still around. Though it sadly doesn't seem to be popular with PC components.

You still get full specs from many companies. Free samples are still around. Though it sadly doesn't seem to be popular with PC components.

It's a little sad that people have to pay that much when all they really need is a $5 PIC and a few throwaway components.

Even the earliest Palm Pilots have a Dragonball processor in them, which is a derivative version of the 68000 processor. The 68000 processor is nothing to scoff at, it's a damn powerful machine for many purposes. If you want to talk about tiny processors, you need to look at things like the PIC10F200 that I've been writing some code for at work. It has 16 bytes of R/W memory and 256 words of program memory. You're not gonna use a C compiler to write your code for a little critter like that, though you can if you really want (don't use a lot of recursion, the stack is two levels deep.) I just noticed that the above linked page says it has 0K of program memory. I suppose rounding to the nearest K, that is true. Really cool little chips, though. Priced at only about $0.40, you can deploy your code just about anywhere you need really cheap.

I'm not sure why everybody automatically leaps to FPGAs. There are lots of cool chips and ideas for how to do neat stuff with them.

My latest project was extremely low-tech but has been useful. I wanted a small timer to time the 2 minutes that each apple tree gets watered out in the field. I used one of the cheapest PIC microcontrollers, a little 8-pin bugger that cost me about $0.40. All self contained so you just hook power and ground to it and it does it's work, I wrote the code for it to blink an LED once per second for 120 seconds then go to micro-low-power shutdown. The pushbutton to start the timer is connected to the hardware interrupt to wake it up from sleep.

That's a decidedly low-end project, but it's just a small example. What I want to do next is design and implement a simple two wire networking protocol so I can program a bunch of PICs to intercommunicate, then scatter them around the house for various functions.

The sky is the limit, and you can do cool and powerful things with FPGAs, but let's not forget that the entry cost for hardware/firmware/software hacking is measured in single dollars these days.

Yes, making a UAV is not trivial, but neither is it incredibly difficult. There are plenty of cheap parts out there that, with a little programming, could tie together a small GPS module and aircraft control servos. It wouldn't be too terribly difficult for any country to make a UAV; I would say with a parts budget of $1K US, I could probably get a simple one (that could fly to a given waypoint) working within a few weeks/months. With $10K, you could make a very capable one -- probably with a range of several hundred km -- which could carry a small payload (a few grams of radioactives go a long way, ya know.)

Bottom line -- trying to restrict such technology is laughable these days. Microchip literally gives away microcontrollers capable of handling a small aircraft, given the right software and interface electronics. These "evil terr-a-rists" will always be able to get their hands on technology. What we need is to find a way to make it politically difficult for them to continue as terrorists. (I.E. find a diplomatic solution.)

Kind regards
Simon H

[1]: Be here all weekend.

will hardware vendors stop releasing 32-bit chips?

Will this increase the amount of lead going into our landfills?

Every time someone asks Slashdot a question like this, the hysteria crowd comes out of the woodwork to scream about how it's absolutely impossible for an "amateur" to do it, and you absolutely must hire a "professional," lest something tragic happen, ranging from the ever-popular "you'll lose your job!" to a bucket of dead puppies or something.

Yes, I realize that professionals are sometimes necessary, especially in situations where life is clearly at stake (pilots, medical, law, etc.) I'm sure some jackass will show up to tell me how this is an industrial furnace and that clearly means that a professional is warranted, but we have no idea what the particulars of this situation are. Just stick to the freakin' question, people.

It used to be the case that "professional" implied not only a degree of competence, but also a certain amount of integrity and experience. But that's just not true any more. All it means now is that someone gets a paycheck for doing something. Often it means that they're experts in nothing more than doing something as cheaply as possible.

For what it's worth, I'm personally fond of the Atmel AVR microcontrollers. Many, many people are also fond of Microchip's offerings in the PIC line. But for rapid development, something like the Parallax BASIC Stamp is probably the way to go. They're cheap and easy (like a good woman) and let you focus on the task at hand rather than the bit-level details of how to read sensors, etc.

Every time someone asks Slashdot a question like this, the hysteria crowd comes out of the woodwork to scream about how it's absolutely impossible for an "amateur" to do it, and you absolutely must hire a "professional," lest something tragic happen, ranging from the ever-popular "you'll lose your job!" to a bucket of dead puppies or something.

Yes, I realize that professionals are sometimes necessary, especially in situations where life is clearly at stake (pilots, medical, law, etc.) I'm sure some jackass will show up to tell me how this is an industrial furnace and that clearly means that a professional is warranted, but we have no idea what the particulars of this situation are. Just stick to the freakin' question, people.

It used to be the case that "professional" implied not only a degree of competence, but also a certain amount of integrity and experience. But that's just not true any more. All it means now is that someone gets a paycheck for doing something. Often it means that they're experts in nothing more than doing something as cheaply as possible.

For what it's worth, I'm personally fond of the Atmel AVR microcontrollers. Many, many people are also fond of Microchip's offerings in the PIC line. But for rapid development, something like the Parallax BASIC Stamp is probably the way to go. They're cheap and easy (like a good woman) and let you focus on the task at hand rather than the bit-level details of how to read sensors, etc.

Use Microchip's IDE, which has a built-in debugger and stimulus editor. Once it runs in the debugger, burn it to a chip and watch it run. Since their processors have built-in I/O devices, you can get a lot done with little or no additional circuitry.

The PICAXE is in essence a Microchip PIC microcontroller with a custom bootloader to load programs into memory and execute them on reboot/reset.

I was sort of expecting a general CPU, even if a vintage chip like the ZiLOG Z80, MOS Technologies' 6502, Motorola's 6800 / 6802, or intel's 8088 / 8086 microprocessors.

It seems more suited to O'Reilly's MAKE magazine and their blog, then on Slashdot.

How about #1 8bit microcontroller market share.

http://ww1.microchip.com/downloads/en/devicedoc/39 746A.pdf

I don't speak for microchip, just work there.

100% agree. Microchip's products are really great as they do a range of devices from cheap and simple devices up to quite complex ones. They are fun to use and quick to learn - sure, in the real world, high level languages like Java are desired by employers, but these are so abstract that you don't get a feel for the actual workings of the computer. Its vital that people understand how the actual machine works, and there's nothing like a bit of assembler and some flashing LEDs and push buttons to do this.

The University of Minnesota just moved to the PIC because of its ease of programming as compared to the Motorola 6800 series microcontrollers that were in use before. The PIC comes in 8 and 16-bit varieties and has a range of available memory sizes. I'm not sure about pricing, but they are somewhat of a standard "learning" microcontroller, so your students will have a leg-up when they get to college.

The Microchip PICmicro is a very good choice. Try the PIC16F84 - the chip is cheap, programmers that connect to a PC parallel port are simple to build, a chip can be electronically erased and reprogrammed hundreds of times.

The assembly language is also very simple. There are only thirty-five instructions and two addressing modes. It's also very easy to calculate instruction timing (for delay loops, etc.). I learned to program those things when I was at high school.

Things like the BASIC stamp are less than helpful. You aren't close enough to the metal. If you don't like the PICmicro, an AVR chip would be my second choice.

I agree, just b/c PCs run at 3GHz today, your dining room creations don't need to. You also should be more specific. What is you background now? Are you a programmer? Are you interested in digital or analog electronics? How much money do you want to put into the hobby? The money part is pretty important, b/c it will dictate the equipment you will have. Electronics hobbyist cover the spectrum of a $5 radio shack soldering wand and components robbed from discarded equipment, to high dollar equipment bought at surplus auctions. For the digital domain, it makes sense to use a microcontroller, b/c it cuts down on component count as compared to logic chips. For a $230 you can get a Microchip ICD2 and development board from www.digikey.com, P/N DV164006-ND. Microchip has a very good user community at http://forum.microchip.com/. If you want to spend less money, there are many plans on the web for do it yourself bootstrap programmers for PICs. I reccomend the ICD2 if you can afford it. It supports a very wide range of parts from Microchip, and the development board will save you a lot of time in building. In the analog domain, the operational amplifier is the heart electronics. A great place to start, if you have not already, is to build math functions with op-amps... dividers, multipliers, integrators, et. As you perfect different analog circuits, you can start to combine them into larger circuits. Depending on the money your willing to invest, there a lot of good books available. The first I would suggest, and I've seen it in other posts in the this thread, is The Art of Electronics. It's a good general reference. Also, it can't be overstated, the wealth of information available on the web in the form of manufacturers datasheets and application notes. www.national.com is a good place to start looking for datasheets. They have some really good online tutorials, check out there analog university, http://www.national.com/AU/. Wikipedia links to some good resources as well in their electronics articles.

the PIC's not bad if you use the right C compiler (you can use Asm too, if you're a stud), but for the beginner, there's nothing like the BASIC Stamp.

yeah, it costs $50 compared to the $2-10 you'd spend on a PIC. you'll get that $40 back after you do something in 15 minutes that would have taken a couple of hours in PIC asm. (I have nothing against assembly language but the PIC's instruction set is very, very slim -- you can't even compare two bytes without having to compare two bits, eight times.)

anyway, get a BS and get going. the rest of electronics can be summed up as V=IR; 70% of electrical engineering is just learning how to apply that equation everywhere you look.

While Z80s are cool, some people prefer microcomputers with RAM, ROM and I/O integrated on the IC. For example:

Microchip or
Atmel

or a small board level device like:

The Basic Stamp

A very cool supplier of microcontrollers and accessories is:

Sparkfun

And the usual suppliers:

Digikey
Newark
Arrow
Mouser

Most people are familiar with the 8-bit Atmel AVR microcontrollers, similar to the Microchip 8-bit PIC microcontollers. The AVR32 is a 32-bit microcontoller. I believe it was developed by Atmel to be a easy to mirgrate to target to compete with Freescale's 32-bit offerings, and various manufacturers' low cost 32-bit ARM processors.

I suspect they could accomplish that by buying Arizona Microchip/Microchip Technology (the PIC people - http://www.microchip.com/)

Depending on how far you want to stretch your definition, how about $0.39 http://www.microchip.com/ParamChartSearch/chart.as px?branchID=1009&mid=10&lang=en&pageId=74

Go to microchip.com, and search for "PIC18F4550." They'll even give you free samples and code to make it work. You can build the programming cable yourself, or buy one. Google for "PIC programmer."

Yup, right on the money. There's a lot to be learned by programming a few micro controllers. It's farily easy to get started too, especially if you go for common hardware such as PICs. Just grab a PICkit 2, an assembler and some software to get your programs onto the chips and you're set.

Doing a search for "PIC projects" on Google should give you some fun ideas to work towards. If you've done at least two years of computer science you should have all the knowledge of assembly you need.

Connector pinouts are some big secret? Can't find any info via google so here you go, I used my beeper to trace the routes:

Master and User are the two processors. You want to pick up the CPU specs here:
http://ww1.microchip.com/downloads/en/DeviceDoc/39 609b.pdf

"Serial" connector, pin 1 is on the right as you look into the connector.

1. User pin 60 "RJ2" through 10K resistor
2. Master pin 60 "RJ2" through 10K resistor
3. Master pin 60 "RJ2" through 1K resistor
4. Gnd
5. User pin 38 "RX1" - serial receive (TTL levels!) through 1K
6. User pin 37 "TX1" - serial transmit (TTL levels!)

Rx1 and Rx2 connectors, pin 1 is on the right as you look into the connector. Both are the same except for pin 2 which is the signal pin.

1. +5V
2. signal (see below)
3. Gnd
4. Gnd

Rx1 Signal pin goes to Master pin 57 "RB1"
Rx2 Signal pin goes to Master pin 43 "RC2" and also pin 56 "RB2" through a 1K resistor.

On the motor connectors, the signal is the pin closest to the "notch" on the connector. The middle one is +5V and the other is Gnd.

More info needed, what speed is the serial running at? What commands can we send it? How does one CPU talk to the other? How can we program the EEPROM on them? If I make my own cable, why can't I just download the software when your cost would be almost zero?

Why would the company want to not release this info and be so anal? It's not really that hard to ohm things out, sheesh! Give us better info!

Even with this info I will still be buying more motors and sensors, and I did by the kit, how else do you think I got your controller?

I presume you mean computers / electronics?

Get one of these. Should be able to get the knight-rider LED thing going in a couple of days, and after that it's all plain sailing.

What? Why are you all looking at me like that?

If you can't do it something like a Microchip PIC, then try a Xilinx FPGA.

If you can do your design in software, a PIC microcontroller http://www.microchip.com/ is about the cheapest option.

Okie dokie, can you help me find a JVM for a PIC 10F200 microcontroller? http://www.microchip.com/stellent/idcplg?IdcServic e=SS_GET_PAGE&nodeId=2061&param=en505736

Microchip is coming out with a 28 pin ethernet interface. Couple that with a PIC microcontroller and an ethernet transformer and you'll have what you're asking for.

Alternately you can get something off the shelf from netsilicon. Add a battery and you're good to go.

-Adam

I just designed a complete computer that uses less than 3 watts! (more details)

Admittedly, it probably does far less than a power based computer. It runs at 1 MIPS, has only 64 bytes of RAM and spends most of its time sleeping, but on the plus side, it costs less than $10 to build and while sleeping uses about .05 watts of power.

Imagine a beowolf cluster of these babies!

It's too clever to be really useful unfortunately. The big issue is of course the no "local variables". Trouble is, if you are writing in C, the compiler may well be creating local variables for you behind your back. In C++ for example there are many cases where this will certainly happen, like

void DoSomething(const string&);
DoSomething("hollow, whirled");

where a local variable of type string will be temporarily created to pass to routine DoSomething.

You need to read the article.

It only says you can't use local variables across functions that block. Actually, it doesn't even say that you can't use them, it only says don't expect their value to be preserved.

In your example, even if the compiler does create a local variable to call DoSomething, and even if DoSomething does block, who cares if the value of that local variable is preserved, since it's impossible to reference it again after that statement?

But that was an awfully long time ago. Now it's hard to find memory chips below 1Mbit.

I can help you with this problem! Is 16 bytes small enough?

And since you can't use local variables, you can't use things like the C libraries or pretty well any library ever written, which is teh sux0r.

But you can use the C libraries. Just don't use local variables across functions that block. Only a very few C library functions block.

The PIC is a complete solution, supported through a local service provider

Look! It's got recurring revenue generation built in! Not only can you pay for it up front, but you can keep paying for it month after month; forever! ALl the while you'll be giving control of it over to your favorite ISP, who can reduce it's functionality at their whim, or upon lawsuit, whichever comes first.

Where do I sign up?

(Also: How long until Microchip slaps them with a trademark suit?)

The PIC is a complete solution, supported through a local service provider

Look! It's got recurring revenue generation built in! Not only can you pay for it up front, but you can keep paying for it month after month; forever! ALl the while you'll be giving control of it over to your favorite ISP, who can reduce it's functionality at their whim, or upon lawsuit, whichever comes first.

Where do I sign up?

(Also: How long until Microchip slaps them with a trademark suit?)

They'd use something like a car alarm. A code-hopping system could be made rather hard to break, though the ones used in actual car alarms aren't:-)/. If you want to read about it, Microchip is one of the companies that make code-hopping transmitter and receiver components - they call it KEELOQ or something.

http://www.microchip.com/stellent/idcplg?IdcServic e=SS_GET_PAGE&nodeId=1406&dDocName=en021925

Around £140 for two nodes if memory serves. I'm not sure I'm that impressed with the state of the stack at the moment, but it serves if you want to have a play.

Use microcontrolers! You can do a lot of stuff with them and are ultra cheap. Think of them as one of those old computers on a chip. :) Coding them in assembly and building circuits for them to interface to is a good challange. Microchip gives free samples of their stuff and has excelent docs.

Sounds like a good course... I wish I had something like that when i was in highschool :). Anyways, for parts, http://digikey.com/ is probably the best. You might also want to check out http://jameco.com/. If you're teaching robotics, you'll probably want some simple MCUs to teach basic microcontroller concepts with. I would suggest a simple PIC micro from http://microchip.com/ or better yet a BASIC stamp from http://www.parallax.com/

The hardware costs could be as little as $10 or so per device, and it would be not much larger than the ATA connector!

even a PIC10F would do :D

I've implemented the 128-bit AES algorithm in a PIC16F873. Here's the Microchip page with the app note and source code. The app note has performance metrics - 5273 cycles to encrypt; 6413 to decrypt (section 6, page 14.) My implementation, written from scratch, has comparable performance.

Since the PIC is a single-cycle execution unit, clocks correlate directly to real-time once you spec the operating frequency. At 40kHz clock (=10kHz instruction execution frequency) it'll take 527mS to encrypt one 128-bit block of data. Similarly, a 400kHz clock results in a 52.7mS block excrypt time. A maximum of 41-bytes of RAM are required for either encode/decode operations.

The claim that AES requires substantial hardware is bogus. AES is designed to be byte-processing friendly. It's much nicer than dealing with the bit-oriented DES and 3DES standards, especially in an 8-bit microcontroller environment.

I this case they made a small module with an ARM7 on it - running a .net runtime.
Did you even read the article :)

Anyway. There are some of this kind of modules around - some with java runtimes.

Atmel has a series of small footprint risc processors with flash, eeprom, sram and various pheripheral io. Easy to program, easy to use.
http://www.atmel.com/dyn/products/param_table.asp? family_id=607&OrderBy=part_no&Direction=AS C

There is also a 6 pad PIC processor http://www.microchip.com/stellent/idcplg?IdcServic e=SS_GET_PAGE&nodeId=2060

None of these runs .net or java as far as i know, but this would be a nice christmas project ;)

I thought that, but then I also thought of the line of microcontrollers made by Microchip.

The HC11 has been nearing the end of its life for years now. You'd be nuts to use that chip in a new design.

Consider using an AVR chip. Its a nice, modern RISC (32 registers, compared to the shitty HC11's handful). They are much cheaper, have a shitload more memory and peripherals, and tons faster (16/24 MIPS). Even a common-as-dirt PIC chip would be better then this.

The tools are much better for PICs and AVRs because they are much more popular.

• Package size: The AT91SAM7A is impressive in how much it packs into a 64-pin TSSOP package, but Atmel's 8-bit ATtiny15L is also impressive in what it packs into an 8-pin SOIC. And if that's too big, Microchip just released the PIC10F 8-bit microcontroller in a 6-pin SOT23 package. Don't sneeze.
• Price: 8 bit MCUs are still cheaper, most under $1 in quantity, while the AT91SAM7A is $3 in quantity.
• Power supplies: The ATtiny15L works with one supply between 2.7V to 5.5V, so it could run off a loosely-regulated supply, or straight off batteries, eliminating the need for a regulator. The AT91SAM7A needs a 3.3V core supply, and a second 5.0V supply if any of the I/O pins need the higher voltage. There are some parts that you still can't get in 3.3V.
• Power consumption: That ATtiny15L takes 3.0 mA active and 0.001 mA sleeping. The AT91SAM7A uses 0.24 mA sleeping and up to 78 mA when running (those figures are buried in the full data sheet). Good to know when battery life is an issue.
• Compiler support: both ARM and AVR architectures are supported by GCC.
• Architecture: Both AVR and ARM architectures are RISC architectures.
• Clock: The AT91SAM7A can run up to 8 MHz with an external crystal or 30 MHz with an external oscillator (using an internal PLL). The AVRs can run to 8 MHz on an internal oscillator (no extra parts) or 16 MHz from an external oscillator (though the ATmega26 has a trick where you can run at 16 MHz from the internal oscillator).

I would have loved to compare to the AT91SAM7S described in the article, but data sheets weren't available on the web site. All that said, I think the more impressive product is on the horizon: the AT91SAM7X series with built-in Ethernet.

Best of luck to the uClinux folks trying to pack everything into 64K of RAM. I've never tried to use less than 1 MB. A better choice, IMHO, would be something like eCos, which can be stripped down more, because in embedded systems, you don't always need a POSIX-style file system hierarchy.

While there have been many advances in 32-bit MCUs, it would be foolish to assume that the 8-bit MCU market is still stuck in the land of the 6502/8051/6800 CISC architectures. It's had its share of advances as well. And nobody really wants to use a 32-bit MCU for a mouse or keyboard.

They're excellent for home projects like this because they are cheap and very easy to use. In many projects you don't need any other ICs and very few extra components. The assembly instruction set is very simple and almost trivial to learn. Or you can use a C compiler (I believe you can get a basic one for free from here).

Check out Microchip.com for information on the different chips available. They range from the small, simple 12 series to the more powerful 18 series (which support things like USB, I2C, CAN, A/Ds, ...)

P.S. No, I don't work for microchip, I just like their products

Your idea of using surplus is only good is you have whatever said surplus already laying around. I don't happen to have any of the old parts you mention (gameboys, zip drives, scanner, etc.) lying around, or you have a large enough surplus supply (electronic goldmine, ocean state electronics, ebay but prices get whacked quickly) on the market.

Experimenting with cheap 8-bit microcontrollers such as Microchip's PIC or Atmel's AVRs is quite cheap, and typically all you need is a chip and one (really cheap if want) device - a programmer to transfer the (binary/hex) programs from your PC to the microcontroller's flash memory.

You will quickly outgrow Radio Shack unless you need a part right now and you don't have the right one in your own stock pile, often referred to as a "junk box" regardless of actual physical size. You should be getting the free catalogs (or CDs) from Digikey, Mouser, Newark, and Jameco. These all have usable online ordering systems and reasonable minimum order & shipping fees. UK geeks check G3SEK's UK Component and Tool Suppliers web page.

Many useful projects can be made for less than $100 even if you need to buy all the parts. After you build a collection of common parts (common resistors, capacitor values, PIC 16F628, AVR AT90S2313, red & green LEDs, 2N2222A, 2N3904, 2N3906, 2N4401, 2N4403, 2N4416, 4N25, 1N4148, 1N4001, 1N4007, etc.) and tools this cost will go down.

The real question is do they assume a general audience or do they assume a "knowledgeable user" is their target market? If the stuff is purely "cookbook" & kit building (AmQRP kits as an example) with little or no encouragement (and knowledge transfer) for the average Make reader to explore and expand it won't survive IMHO. BTW AmQRP kits on their own are pretty limited at expanding your knowledge, but combined with the AMQRP Homebrewer magazine and Conference Proceedings they do teach a lot. There is also the QRP-L mailing list which is very useful for technical questions (and has a rich archive)

I think it should be what Nuts and Volts magazine tries to be, but without the "legacy" dead weight and filler articles. A gentler introduction to most of the Circuit Cellar type stuff.

If people think this will recreate the Homebrew Computer Club, I expect they will be mistaken, but if you expect it to awaken the curiousity and encourage youth to learn about electronics, then I hope it is a brillent success.

In the end, I am curious and not quite sure what to expect of Make. It could be really lame if all it ends up being is computer geeks pretending to be electronic engineers (or electronic hobbyists). I hope that at least 10% of it expands what I know, which is more than I can say of books like Hardware Hacking Projects for Geeks (O'Reilly) and Hardware Hacking: Have Fun While Voiding Your Warranty. I am more interested in reading stuff like Hacking the Xbox (An Introduction to Reverse Engineering) by Andrew "bunnie" Huang which starts simple but gets into FPGAs and reverse engineering.

It'll be an RFID chip. See: This example RFID chip from Microchip Inc.

Just use a cheap microcontroller, perhaps a PIC. They are pretty simple to get the hang of, just a handful of RISC instructions, and they're cheap. All the protocol information is available readily